G670 Intermittent Pilot Ignition Controls Technical Bulletincgproducts.johnsoncontrols.com/met_pdf/121240.pdf · G G670 Intermittent Pilot Ignition Controls Technical Bulletin 5 9

Installation Sheets Manual 121Gas Combustion Combination Controls and Systems Section G

Technical Bulletin G670Issue Date 0300

© 2000 Johnson Controls, Inc. 1Part No. 24-8143-162, Rev. B www.johnsoncontrols.comCode No. LIT-121240

Figure 1: G670 Intermittent Pilot Ignition Control

The G670 is a Non-100% Lockout Intermittent Pilot Ignition (IPI) controlthat replaces the G67AG and G67BG ignition controls. The G670 is used toautomatically light a pilot burner and energize the main burner gas valve inresponse to a call for heat from the system thermostat. When the call for heatis satisfied, the thermostat opens and the G670 de-energizes the pilot andmain burner gas valves.

Following are the application requirements of the G670 control.

• The G670 can be used with equipment with a maximum firing rate of117 kW (400,000 Btu/hr). Any application greater than 117 kW(400,000 Btu/hr) must have written approval in advance from theHeating Products Engineering Department.

• All G670 applications must use a redundant gas valve system with themain valve seats in series.

G670 Intermittent Pilot Ignition Controls

Description

ApplicationRequirements

2 GG670 Intermittent Pilot Ignition Controls Technical Bulletin

Table 1: SpecificationsIgnition Type Indirect

Ignition Source High voltage spark, capacitive discharge

High Voltage CableLength

915 mm (36 in.) maximum

Flame Detection Means Flame rectification

Flame Detection Types Remote sensing

Minimum Flame Current 0.2 microampere

Flame Failure ResponseTime

0.8 second, maximum

Spark Gap 2.5 mm (0.1 in.) nominal

Ignition Trial Time Infinite

Power Requirements Control: 24 VAC, 50/60 Hz, nominalOperation Current: 0.15A nominal + valves

Contact Rating Main Valve: 2A continuous, 5A inrushPilot Valve: 2A continuous, 5A inrush

Ambient Operating andStorage Temperature

-40 to 66°C (-40 to 150°F)

Humidity 95% RH non-condensing

Types of Gas Natural(Liquefied Petroleum [LP], manufactured, mixed, orLP gas-air mixture may be used in a well vented oroutdoor application.)

Agency Listing CSA (AGA/CGA) Certificate Number 112520-0-19

Specification Standards ANSI Standard Z21.20CSA C22.2-No. 199

The performance specifications are nominal and conform to acceptable industrystandards. For application at conditions beyond these specifications, consult thelocal Johnson Controls office. Johnson Controls, Inc. shall not be liable fordamages resulting from misapplication or misuse of its products.

The following definitions describe operating conditions.

• Trial for Ignition--Period during which the pilot valve and spark areactivated attempting to ignite gas at the main burner. Thetrial-for-ignition period is infinite for the G670s and ends once thepilot flame is detected or the call for heat ends.

• Run--The main valve remains energized and the spark is turned offafter successful ignition.

• Flameout--Loss of proven flame. Should a flameout occur, the mainvalve closes and the spark recurs within 0.8 second.

OperatingModeDefinitions

GG670 Intermittent Pilot Ignition Controls Technical Bulletin 3

Figure 2 illustrates the sequence of operation for the G670 ignition control.

On a call for heat from the system thermostat, the G670 simultaneouslyopens the pilot valve and supplies a continuous spark to the pilot burner’selectrode. When the pilot burner gas ignites, the pilot flame sensor detectsthe pilot flame and signals the G670 to energize the main gas valve anddiscontinue the spark. The main gas valve will not be energized until theflame sensor detects the presence of the pilot flame.

If the pilot flame goes out (with the thermostat still calling for heat), theG670 will de-energize the main gas valve and provide a continuous sparkat the pilot burner’s electrode. When the pilot flame is re-ignited anddetected by the pilot flame sensor, the main gas valve is energized and thespark is shut off. The G670 de-energizes the pilot gas valve and mainburner gas valve when the thermostat stops calling for heat.

Start

Flameout?

No

No

Yes

No

Yes

Run

No

Yes

End

Yes

De-energize ControlPilot and Main Valves

ThermostatCalling for

Heat?

De-energizeMain Valve

EnergizeMain Valve

PilotFlame

Sensed?

Trial forIgnition

FlamePresent?

ThermostatCall for Heat

Figure 2: Sequence of Operation

Sequence ofOperation


IMPORTANT: These instructions are intended as a guide for qualifiedpersonnel installing or servicing Johnson Controlsignition controls. Carefully follow all instructions inthis bulletin and all instructions on the appliance. Limitrepairs, adjustments, and servicing to the operationslisted in this bulletin or on the appliance.

! WARNING: Fire or Explosion Hazard. Avoid serious injury bycarefully following precautions in this bulletin and allinstructions on the appliance. Limit repairs,adjustments, and servicing to the operations listed inthis bulletin or on the appliance.

! WARNING: Fire or Explosion Hazard. If the control is installedin an area that is exposed to water (dripping, spraying,rain, etc.), it must be protected. If the control has beenexposed to water in any way, do not use it.

! WARNING: Shock Hazard. Avoid electrical shock and equipmentdamage. Disconnect electrical power and turn off thegas before wiring the control.

! CAUTION: Equipment Damage Hazard. Label all wires prior todisconnection when servicing controls. Wiring errorscan cause improper and dangerous operation. Verifyproper operation after servicing.

Perform the following procedure to install the G670 ignition control.

1. Shut off power to the appliance.

2. Turn off gas at the manual shutoff valve adjacent to the appliance.

3. Label each wire with the correct terminal designation prior todisconnection.

4. Disconnect the power supply (transformer) and the thermostat leadwire at the ignition control.

5. Disconnect the sensing probe lead from Terminal 4 on the ignitioncontrol.

6. Disconnect the high voltage cable from the spark transformer.

7. Disconnect the Pilot Valve 1 and Main Valve 3 leads from the ignitioncontrol.

8. Disconnect any wires connected to the ground terminals on the ignitioncontrol.

Installation

Mounting


9. Remove the screws holding the ignition control assembly in place.

10. Remove the ignition control and discard.

11. Using the same holes as the old ignition, mount the new G670 controlon a grounded metal surface with metal screws or bolts through themounting holes provided on the enclosure.

All spark ignition controls have a spark transformer connected to a highvoltage cable. There are three types of connection for the high voltagecable: Spike, Rajah, and 6.35 mm (1/4 in.) male spade (see Figure 3). TheG670 has a Spike transformer. When replacing a control that has a Rajahor male spade connection, the crimp-on connector must be cut off.

1. Slide the rubber boot up the cable.

2. Cut the lead just above the connector (see Figure 4). Make a straightcut perpendicular to the cable.

3. Center the exposed wire on the end of the lead over the spike in thespark transformer and push the wire lead down firmly over the spike(see Figure 5).

4. Ensure the lead is inserted all the way into the spark transformer. Slidethe boot back down the cable and over the spark transformer.

Spike Connection Rajah Connection 6.35 mm (1/4 in.)Male Spade

Figure 3: High Voltage Cable Connectors

High Voltage Cable

Insulating Boot Crimp-onConnector

Cut off connector here.

Figure 4: High Voltage Cable with Crimp-On Connector

High Voltage Cable

Spike must be in contact with the center wires.

Figure 5: Spark Transformer Connection

ModifyingExisting IgnitionCable


! CAUTION: Equipment Damage Hazard. Connect the highvoltage cable to the spark transformer terminal andspark electrode (pilot burner assembly) beforeapplying power to the control. Ensure the ground wireis attached to the pilot burner and control groundterminal strip.

! CAUTION: Equipment Damage Hazard. Locate all limit andoperating controls in series with the thermostatterminal (THS 2) on the ignition control.

Check the voltage rating marked on the control and make sure it is suited tothe application. Use a National Electrical Code (NEC) Class 2 transformerto provide 24 VAC under maximum load, including valves. A transformerhaving excessive primary impedance due to poor coupling will affect theignition potential.

Refer to Figures 6 through 9 for wiring diagrams. All wiring should be inaccordance with the NEC and all other local codes and regulations. Thehigh voltage spark transformer cable must not be in continuous contactwith a metal surface. Use standoff insulators. Ensure that the flame sensorwire and the high voltage spark transformer cable are separated fromone another by a minimum distance of 6.35 mm (1/4 in.) and are notwrapped around any pipe, other wiring, or accessories.

Wiring


0.21 in

RW Y

Thermostat

1 6 2 4 3

Jumper

Ground Terminals5

PVMV

Limits inthe Thermostat

Line Only

24VAC

PowerSupply

FlameSensor

High VoltageCable

PilotBurnerGround

Figure 6: Replacement Wiring Diagramif the Original Control is a G67AG

RW Y

Thermostat

1 2 4 3

Jumper5

6

MV PV

Limits inthe Thermostat

Line Only

24VAC

PowerSupply

PilotBurnerGround

GroundTerminals

FlameSensor

High VoltageCable

Install the jumper suppliedwith the replacement controlbetween Terminals 2 and 6.

Figure 7: Replacement Wiring Diagramif the Original Control is a G67BG


RW Y

Thermostat

1 6 2 4 3

Jumper5

MV

PV

Y79

PVMV

High VoltageCable

FlameSensor

PilotBurnerGround

24VAC

PowerSupply

High LimitsIn This Line Only

Black

Brown

White

Install the jumper suppliedwith the replacement controlbetween Terminals 2 and 6.

Figure 8: Wiring Diagram for G670 with Y79B _ _

RW Y

Thermostat

1 6 2 4 3

Jumper

Y79THS

MV PV

5

FlameSensor

High VoltageCable

PilotBurnerGround

24VAC

High LimitsIn This Line

OnlyPowerSupply

White

Red

Black

Figure 9: Wiring Diagram for G670 with a Y79A _ _


! WARNING: Fire or Explosion Hazard. Avoid personal injury orproperty damage by making sure the control functionsproperly and there are no gas leaks. Follow thischeckout and startup procedure before leaving theinstallation.

! WARNING: Fire or Explosion Hazard. Do not attempt to checkout this system by manually lighting the pilot. Thiscould energize the main valve.

Make sure all components are functioning properly by performing thefollowing shutoff test.

1. With the gas and thermostat off, turn on power to the appliance.

2. Turn on the thermostat to the highest setting and verify that the controlgoes through the operating sequence to a shutoff condition.

Note: The burner will not light because the gas is off.

3. Turn off the thermostat.

4. Turn on the gas and purge gas lines of all air.

5. Test for gas leaks on all pipe joints and connections upstream of thegas valve with a soap solution.

6. Turn on the thermostat to the highest setting and verify successfulignition and a normal run condition for at least three minutes. If theappliance fails to run, see the Service Checkout Procedures section.

7. Test for leaks on all pipe joints and connections downstream of the gasvalve with a soap solution.

8. Turn the thermostat down for at least 30 seconds and then back upagain. Verify successful ignition at least three times.

9. Return the thermostat to a normal temperature setting before leavingthe installation.

Checkout andStartupProcedure


The thermostat anticipator setting is normally equal to the ignition systemcurrent draw, plus that of the pilot and main valve.

Due to variations in appliance wiring and valves, it is advisable to measurethe actual current draw of the heating system at the thermostat location.Measuring this current can be accomplished by opening the thermostatcontacts (lowering the set point) and installing an AC ammeter across theterminals, or by using a clamp-on ammeter with a 10-turn multiplierattached to the terminals (see Figure 10).

IMPORTANT: Measuring the current with an ammeter will energizethe system. Wait until the gas valve and inducerenergize before taking a current draw measurement.

Ten Turns

W R

W R

AC Ammeter Low Scale Setting

Clamp-on Ammeter(Divide reading by ten.)

ToHeatingSystem

ToHeatingSystem

Figure 10: Measuring the Thermostat Current

ThermostatHeatAnticipatorSettings


If the system does not function properly, determine the cause using theprocedures in this section.

Before proceeding with troubleshooting the system, check the following:

• Are all mechanical and electrical connections tight?

• Is the system wired correctly?

• Is the gas inlet pressure per the manufacturer’s specifications?

• Is the system powered?

• Is the thermostat calling for heat?

There are three potential system failure conditions:

• no spark, and system does not work

• spark is present, but pilot does not light

• pilot lights, but main valve does not come on

Determine the failure condition, then use the respective flowcharts on thefollowing pages to troubleshoot the system. Perform the procedures in theCheckout and Startup Procedure section after any servicing.

! CAUTION: Label all wires prior to disconnection when servicingcontrols. Wiring errors can cause improper anddangerous operation. Verify proper operation afterservicing.

Do not attempt field repairs. Use only exact or factory recommendedreplacement controls.

All other accessories, such as flame sensors, electrode assemblies, pilotassemblies, and leads can be obtained through the original equipmentmanufacturer or a Johnson Controls distributor.

TroubleshootingProcedure

PreliminaryChecks

FailureConditions andCorrectiveAction

Repairs andReplacement


No

Yes

No

Yes

Yes

No

No

No

Yes Yes

No

No

Yes

Yes

No

Yes

NoYes

Yes

No

No

Yes

Repair

Start

Repair

End

ReplaceG670

Is 24 VAC presentbetween Terminal 6

and ground?


and ground?

Turn offsupply voltage

Visuallycheck. Is Lead 5

connected securelyto ground?

Connectsecurely


and ground?

Is circuit wiringproviding 24 VAC to

Terminal 2?

Are thermostatand limit contacts

closed?

Closecontacts

Check for propervoltage at transformerprimary and secondary

Is circuitwiring providing 24 VAC

to Terminal 6?

Replacecable

Is high voltagecable in good condition

(not brittle, burnt, orcracked)?

Turn onsupply voltage

Connectsecurely

Is spark gap0.1 in. and located in

pilot gas stream?

Is sparkelectrode ceramic

cracked?

Correct or replacepilot burner

Replace pilotburner

Turn onsupply voltage

Operate systemseveral complete

cycles

ReplaceG670

Is high voltagecable connected to spark

transformer?

In some instances ajumper is used betweenTerminals 2 and 6 to power Terminal 6.

Note:

Figure 11: No Spark, and System Does Not Work


Yes

No

Yes

No

No

Yes

Yes

No

No

Yes

Start

Is gas at pilot?

End

Is pilot valve wiringsecurely connected to

Terminal 1 and ground?

Connectsecurely


and ground?

ReplaceG670

Make sure pilot line is notkinked or obstructed. Check

for clean orifice.

Is inlet gas pressureper manufacturer’s

specifications?

Replacepilot valveCorrect gas

pressure

Is pilot spark gap0.1 in. and located in

pilot gas stream?

Correct orreplace pilot

Check for drafts. Shieldas necessary and check

for clean orifice.

! WARNING: Explosion Hazard.Do not use a match to test for presence of gas.

Figure 12: Spark is Present, but Pilot Does Not Light


Correct

End

Correct

No No

No

No

No

No No

No

No

No

Yes

Yes

Yes

Yes Yes

Yes

Yes

Yes

Yes

Yes

StartDoes spark stay on

for more than 30 secondsafter the pilot lights?

Is 24 VACbetween Terminal 3

and ground?


specifications?

Correctgas pressure

ReplaceG670Make sure sensor cable

and high voltage cable areseparated and not wrapped

around any pipe or accessories.

Is sensor cablesecurely connectedto Terminal 4 and

flame sensor?

Connectsecurely

Is mainvalve wiring

securely connected toTerminal 3 and

ground?

Replacemain valve

Is sensorceramic cracked?

Is cablegrounded out?

Is sensor orsensor connector

shorted out to metalsurface?

Is therecontinuity and good

insulation in thesensor cable?

Replacecable

Disconnect main valvelead from Terminal 3

Disconnect sensorcable from Terminal 4

Replacesensor

Connect DC microammeterbetween sensor cable terminal andTerminal 4. Observe correct polarity.

See Figure 20.

ReplaceG670

Is DC current0.2 microamperes orgreater with pilot only

operation?

Check for:- proper gas pressure- clean pilot assembly- tight mechanical and electrical connections

If there is not improvement, change theflame sensor length or the orifice size andperform any necessary turn down tests.

Connectsecurely

Figure 13: Pilot Lights, but Main Burner Does Not Come On


No

Yes

Yes

No

Yes

No

NoNo

YesTurn off supply voltage

No

No

Yes

Yes

Yes

Yes

Yes

NoYes

No

Start

No

Turn supply voltage on

EndOperate system several complete cycles

Is system wiringper manufacturer’s

instructions?

Correctwiring

Open thermostatcontacts for30 seconds

Close thermostatcontacts and wait 30%of the Y79 lockout time

Is aspark

present?

System wasin lockout

Determine reason for lockout.Conduct microamperage test as

outlined in Figure 16,starting at A .


and ground?

ReplaceG670

Check the high voltagecable. Is it securely

connected to the sparktransformer?

Connectsecurely

Turn supplyvoltage on

Is 24 VAC presenton secondary

of transformer?

Replace the transformer ifproper voltage is presenton primary of transformer.

Is highlimit

closed?

Resethigh limit

Replacecable

Is condition of highvoltage cable good(not brittle, burnt,

or cracked)?

Is sparkelectrode

ceramic cracked?

Is spark gap0.1 in. and

located in pilotgas stream?

ReplaceG670


burner

Replacepilot burner


and ground?

Replace the Y79 withthe appropriate

G600 Ignition controls(contact Johnson Controls

Technical Support).

Figure 14: G670/Y79B No Spark, and System Does Not Work


Yes

No

Connect securely

Yes

No

No

Yes

CorrectNo

Yes

Yes

No

Yes

No

Start

If OK, replace pilot valve.End

Are pilot valve andmain valve connections

secured to the proper Y79terminal and ground?

Open thermostat contactsfor 30 seconds

Close thermostatcontacts


and ground on the G670?Wait 30% of the Y79

lockout time.

Is 24 VAC presentbetween ground and pilot valve terminals

of Y79?

Is inletpressure per

manufacturer’sspecifications?

Is gasat pilot?

Make sure the pilot line is notkinked or obstructed. Check

for a clean orifice.

Is spark gap0.1 in. and located inthe pilot gas stream?

Correct or replacepilot burner

Check for drafts.Shield as necessary andcheck for clean orifice.

ReplaceG670



G600 ignition control(contact Johnson Controls

Technical Support).

Figure 15: G670/Y79B Spark is Present, but Pilot Does Not Light


Yes

No Yes No

Yes

No

No

Yes

No

Yes

No

Yes

Start

Yes

No

Yes

NoCorrect

No

Yes

Yes

No

End

A

No

Does spark stay onfor more than 30 seconds

after pilot lights?

Make sure sensor cableand high voltage cable areseparated and not wrapped



and ground?

ReplaceG670

Is 24 VAC present betweenmain valve terminal on the Y79

and ground terminal on the G670?


specifications?

Correctgas pressure


flame sensor?

Connectsecurely


Is main valve wiringsecurely connected tothe main valve terminalon the Y79 and ground?

Connectsecurely

Replacemain valve





Replacecable


Correct

Replacesensor




See Figure 20.


operation?

ReplaceG670


If there is no improvement, change the flamesensor length or the orifice size, then performany necessary turn down tests.


G600 ignition control (contact Johnson Controls

Technical Support).

Figure 16: G670/Y79B Pilot Lights, but Main Burner Does Not Come On


No

Yes

Yes

No

Turn supply voltage on

Yes

No

No

No

YesTurn off supply voltage

No

No

Yes

Yes

No

Yes

Yes

No

No

Start

Yes

Operate system several complete cyclesEnd

Yes

Is system wiringper manufacturer’s

instructions?

Correctwiring

Open thermostatcontact for30 seconds

Close thermostatcontacts and wait 30%of the Y79 lockout time

Is aspark

present?

System wasin lockout

Determine the reason for lockout.Conduct microamperage test as

outlined in Figure 16, starting at A .


and ground?

Check the high voltagecable. Is it securely

connected to the sparktransformer?

Connectsecurely

Is 24 VACpresent between

Terminal 1and ground?

ReplaceG670Is 24 VAC present

on secondaryof transformer?

Replace transformer ifproper voltage is presenton primary of transformer

Is highlimit

closed?

Resethigh limit

Turn supplyvoltage on

Replacecable

Is condition of highvoltage cable good(not brittle, burnt,

or cracked)?

Is sparkelectrode ceramic

cracked?

Replacepilot burner

Is spark gap0.1 in. and

located in pilotgas stream?

ReplaceG670


burner


G600 ignition control(contact Johnson Controls

Technical Support).

Figure 17: G670/Y79A No Spark, and System Does Not Work


Yes

NoStart

No

Yes

Yes

No

No

Yes

End

Is pilot valve wiringsecurely connected to

Terminal 1 andground?

Connectsecurely

Make sure pilot line is notkinked or obstructed. Check

for clean orifice.

Replacepilot valve

Is gas at pilot?Is inlet gas pressureper manufacturer’s

specifications?

Correct gaspressure

Is pilot spark gap0.1 in. and located in

pilot gas stream?


Check for drafts. Shieldas necessary and check

for clean orifice.


Figure 18: G670/Y79A Spark is Present, but Pilot Will Not Light


Correct

End

Correct

No No

No

No

No

No No

No

No

No

Yes

Yes

Yes

Yes Yes

Yes

Yes

Yes

Yes

Yes

StartDoes spark stay on

for more than 30 secondsafter the pilot lights?


and ground?


specifications?

Correctgas pressure

ReplaceG670Make sure sensor cable

and high voltage cable areseparated and not wrapped



flame sensor?

Connectsecurely

Is mainvalve wiring

securely connected toTerminal 3 and

ground?

Replacemain valve







Replacecable



Replacesensor


See Figure 20.

ReplaceG670


operation?


If there is not improvement, change theflame sensor length or the orifice size andperform any necessary turn down tests.

Connectsecurely

Figure 19: G670/Y79A Pilot Lights, but Main Burner Does Not Come On


1 6 2 4 3

Jumper

5

Positive Leadto Terminal 4

Negative Leadto Flame Sensor

ElectrodePilot BurnerAssembly

Y99AU-2 Multimeter

Figure 20: Meter Hookup to Measure Flame Sensing Circuit


Notes


Notes


Notes

Controls Group www.johnsoncontrols.com507 E. Michigan Street FAN 121P.O. Box 423 Installation Sheets ManualMilwaukee, WI 53201 Printed in U.S.A.

Documents

G670 Intermittent Pilot Ignition Controls Technical Bulletincgproducts.johnsoncontrols.com/met_pdf/121240.pdf · G G670 Intermittent Pilot Ignition Controls Technical Bulletin 5 9